How to create Kubernetes Namespace if it does not Exist?

i wouldn’t go for any other solution except the following code snippet:

kubernetes 1.19 and above (included)

kubectl create namespace <add-namespace-here> --dry-run=client -o yaml | kubectl apply -f -

kubernetes 1.18 and below (included)

kubectl create namespace <add-namespace-here> --dry-run -o yaml | kubectl apply -f -

it creates a namespace in dry-run and outputs it as a yaml. The output will be passed as stdin to kubectl apply -f –

The last hyphen is important while passing kubectl to read from stdin.

Also see the examples in:

kubectl apply --help